2015/04/14 by Minggang Zeng, Chen Fang, Zeng, Minggang +14 · 12 citations
Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Topological Materials and Phenomena #cond-mat.mes-hall
paper · pdf · doi:10.48550/arxiv.1504.03492
four pages, three figures
arxiv created 2015/04/14 · openalex publication_date 2015/04/14 · arxiv updated 2015/04/15 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We use first principles calculations to study the electronic properties of rock salt rare earth monopnictides LaX (X=N, P, As, Sb, Bi). A new type of topological band crossing termed `linked nodal rings' is found in LaN when the small spin-orbital coupling (SOC) on nitrogen orbitals is neglected. Turning on SOC gaps the nodal rings at all but two points, which remain gapless due to C4-symmetry and leads to a 3D Dirac semimetal. Interestingly, unlike LaN, compounds with other elements in the pnictogen group are found to be topological insulators (TIs), as a result of band reordering due to the increased lattice constant as well as the enhanced SOC on the pnictogen atom. These TI compounds exhibit multi-valley surface Dirac cones at three M-points on the (111)-surface.